The three frontrunners for the Conservative leadership — Kevin O’Leary, Kellie Leitch and Maxime Bernier — have seen their support slip in the latest iPolitics CPC Leadership Tracker, powered by Mainstreet Research.

And Andrew Scheer is on the cusp of making it a four-way way race at the top as more current members settle on a first choice.

From February 13 to 17, Mainstreet reached 1,895 Conservative party members and found — with a margin of error of +/- 2.24 per cent, 19 times out of 20 — Kevin O’Leary was the first choice for 20.98 per cent of members, followed by Leitch (16.2 per cent) and Bernier (15.3 per cent).

The decline in support for O’Leary and Bernier from the February 9 and 12 poll was within the margin of error, whereas Leitch’s was outside the margin. The number of undecided members also dropped from 11.8 per cent to to 7.0 per cent.

The story of the week, however, is Andrew Scheer, whose support has more than doubled — from 4.6 per cent to 9.9 per cent of members.

“I think he’s stealing a bit from all of the top three. This is where I would have expected to see him, and where I think a lot of people would have expected to see him a long time ago. He needs to sustain this momentum for another month to really be in contention,” said Mainstreet Research president Quito Maggi.

“That’s not easy.”

Another important finding from this week’s poll is Kevin O’Leary’s polarizing effect on Conservative members.

Among all members, 23.8 per cent rank O’Leary as their last-choice candidate — up slightly from 22.09 per cent last week.

When it comes to decided voters, that number rises to 33.1 per cent.

“Fully one-third of the current voters are not accessible to him anymore,” Maggi said, pointing out that this poll captures the membership’s reaction to O’Leary’s debate performance in Montreal last week.

In Montreal, O’Leary declared the debates on women’s reproductive rights and marijuana legalization were over and that the party would defend the LGBTQI community under his leadership.

“Now we’re seeing the effect of that,” Maggi said.

How that opposition will affect his chances of winning the leadership may depend on his ability to sign up new members, Maggi added.

There are five weeks left in which to do that, because only those who are members as of March 28 will be eligible to vote.

Since the vote is a ranked ballot in which all 338 ridings are worth 100 points, Maggi said every path to victory includes substantial second-choice support.

“Let’s assume that the 33 per cent represents 30,000 members. We know that the membership base is around 90,000 right now. That means (O’Leary) needs to sell memberships to maintain his position,” Maggi said.

“He could overcome that 30,000 not considering him at all, but that’s a big hole to dig himself out of. Does he change tack or does he have enough confidence in the new memberships that he’s out there selling?”

The iPolitics CPC Leadership Tracker, powered by Mainstreet, will be tracking the Conservative leadership race until members pick the next leader on May 27. For additional information on methodology and to subscribe to in-depth updates, click here.